Do we need GM to feed the world? It's not as simple as it seems

Is this the week of the great GM fightback? First a much-hyped report by the Government’s Foresight Unit appeared to endorse it as an important solution to world hunger. And then Nobel laureate Sir Paul Nurse, the new President of the Royal Society, devoted part of a BBC Horizon programme to puzzling why the British public fails to endorse the majority scientific view that genetic modification is beneficial, useful and necessary.

Indeed there has been a growing commentariat chorus over recent years that the technology is essential if the world is to be fed. And, at first sight, this seems to make eminent sense. As the world’s population heads towards 9 billion and the amount of available cropland shrinks as cities spread and soil is eroded away, yields clearly have to be increased. And what better way could there be of doing so than to use a technology capable of altering the genetic structure of a plant to make it produce more?

And yet, the world’s biggest ever agricultural study – the work of 400 scientists and 60 governments, headed by Dr Bob Watson, now Chief Scientist at Department of the Environment, Food and Agriculture – concluded that GM was not the simple answer to poverty. In truth, it could even do more harm than good.

For a start there is the inconvenient truth that it is far from clear that genetic modification does increase yields. The biotech industry cites evidence to support its insistence that it does, but other studies actually show a decrease. One, at the University of Nebraska, for example, revealed that five different GM soyas produced an average of 6.7 per cent less than their closest unmodified relatives, and ten per cent less than the most productive conventional soyas available at the time.

The results suggest two factors are responsible. First, it takes time to modify a plant and, in the meantime, better and higher yielding conventional ones are being developed. And second, the fact that GM plants did worse than their nearest unmodified relatives suggests that the very process of modification lessens productivity.

Of course, it may well be that biotechnology eventually overcomes these obstacles to produce unambiguously higher yielding crops. But even that will not necessarily answer world hunger. For increasing food production, though sorely needed, does not of itself solve hunger. India now has both a grain surplus, and hundreds of millions of hungry people, because the poor cannot afford to buy the food they need.

Any realistic hunger-beating strategy has to help poor people earn more – or grow more food for themselves, for many of the world’s hungry are themselves small farmers. GM seeds are more expensive than conventional ones, and so they can’t afford them and they tend to be bought by richer farmers instead. If they were to succeed in increasing yields the rich are likely to use their increased economic power to drive the poor off their land. This happened during the Green Revolution, which greatly increased yields but often led to greater hunger.

Besides it is becoming clearer that GM crops lead to greater problems with superweeds, and have other environmental drawbacks, while concerns that they may have health effects remain unresolved – there simply have not been enough good studies carried out to show whether they are justified or not.

None of this is necessarily irresolvable, of course. GM crops may be developed and used in ways that genuinely benefit poor farmers and enable them to grow more food – though biotech companies have so far shown little interest in making this happen. The health concerns may be shown to be baseless and some, so far unforeseeable, way around the environmental drawbacks may be discovered. But that is a long way from the simple impression that came across from Sir Paul’s programme.

And, in fact, the Foresight report is far less gung-ho than the hype suggested. GM crops are just one of a number of technologies it endorsed, including the much-traduced organic agriculture.

Indeed Government Chief Scientist Prof Sir John Beddington’s endorsement of modified crops, as the report was published, was far from unqualified. “If there are genetically modified organisms that actually solve problems that we can’t solve in other ways and are shown to be safe from a human health point of view, and safe from an environmental point of view,” he said, “then we should use them”. Few would quarrel with that – but so far, at least, these don’t seem to be available.